Just as a comparison in case you don't have it, my M4F has .420 lift 8/48 I and 48/8 E @236 degrees. I have 2 Holley/Webers that outflow the 390 4bbl and it performs great but with a little more bottom end than the higher RPM 290 which these older engines don't like unless they're totally built for it. It's also a little rumpy which I like. Sort of reminds me of those early Buick V8 sounds.
